NH35 vs. NH34: What’s the Difference?

If you’ve spent any time looking at automatic watches or watch-building parts, you’ve probably come across the NH35 and NH34.

Both are automatic movements from TMI, part of the Seiko Group, and both are popular choices for custom watch builds. They share a lot in common, but there’s one major difference: the NH34 adds GMT functionality.

Here’s what that actually means.

What Is the NH35?

The NH35 is a straightforward automatic movement with three hands and a date display.

It’s become one of the most commonly used movements in custom watch building because it does the basics well. It’s automatic, can also be wound by hand, and supports hacking, which means the seconds hand stops when you pull the crown out to set the time.

For a watch that only needs hours, minutes, seconds, and a date, the NH35 is usually all you need.

Its simplicity is part of the appeal. There aren’t many complications to think about, and there is a huge selection of compatible parts available for builders.

What Is the NH34?

The NH34 starts with a similar idea but adds a fourth hand for GMT.

That extra hand makes one full rotation every 24 hours rather than every 12. Paired with a dial or bezel that has a 24-hour scale, it can display another time zone alongside your local time.

So if it’s 3:00 PM where you are, the regular hour hand works exactly as expected while the GMT hand can be set to show the time somewhere else.

You don’t have to be traveling to make use of it. Some people set the GMT hand to UTC, their home time while traveling, or the time zone of family or coworkers.

And some people simply like the look of a four-hand GMT watch.

NH35 vs. NH34

The easiest way to choose between them is to decide whether you want GMT functionality.

Choose an NH35 when you want a traditional three-hand automatic watch with a date.

Choose an NH34 when you want an additional 24-hour hand and the ability to track another time zone.

The GMT complication also affects the rest of the build. An NH34 requires a dial with the correct center opening and enough clearance between the movement, hands, dial, and crystal for the additional GMT hand.

That means you shouldn’t assume every part designed around an NH35 will automatically work with an NH34.

Why We Use Them

For Bexford, both movements give us a solid platform to build around.

The NH35 works well for everything from simple everyday watches to dive-inspired builds. The NH34 gives us the same opportunity to experiment with GMT designs and different combinations of 24-hour bezels and dials.

They’re also movements that make sense for people who want to build their own watches. Parts are widely available, there’s a large watch-building community around them, and you don’t need an exotic movement to put together something interesting.

Which One Should You Choose?

If you’re buying a finished watch, the decision is mostly about whether you want a GMT.

If you’re building one yourself, think about the watch you want to end up with before choosing the movement.

For a clean three-hand build with a date, start with the NH35.

If the design calls for a GMT hand or you actually want to track another time zone, start with the NH34 and choose the rest of the components around it.

Neither movement is inherently the better choice. They’re built for slightly different jobs.

And that’s really the point: start with what you want the watch to do, then build from there.